In $Drosophila$, the allele for a normal grey body colour $G$ is dominant to ebony body $g$. The following table summarises the results of several crosses:

$S.No$	Cross	Result
$I.$ Strain $1 \times gg$	All wild type
$II.$ Strain $2 \times gg$	$1$ wild type $: 1$ ebony
$III.$ Strain $3 \times gg$	All ebony
$IV.$ Strain $4 \times Gg$	$3$ wild type $: 1$ ebony

Which strains both have the genotype $Gg$?

• A
  $I$ and $III$
• B
  $I$ and $IV$
• C
  $II$ and $III$
• D
  $II$ and $IV$